1. Technical Field
The present disclosure relates to a touch screen, and more particularly, to a control circuit and noise removal method for a touch screen, which remove a noise introduced into the touch screen.
2. Related Art
A Touch Screen Panel (TSP) is configured to detect a user's touch using a resistive type, a capacitive type, or an infrared type. In recent years, the capacitive type is chiefly used as the touch screen panel. The capacitive type touch screen panel is advantageous in super visibility, durability, and a multi-touch function in middle and small-sized mobile product groups. In particular, a mutual capacitive type touch screen panel is chiefly used.
A touch screen using a capacitive type panel has a low Signal to Noise Ratio (SNR) due to various noises. Noises that affect the touch screen may be divided into a random noise and a periodic noise. The random noise may include a display noise. The periodic noise may include a 60 Hz noise generated in a fluorescent lamp and a 40 to 50 KHz noise generated in a three-wave inverter lamp. In particular, the periodic noise may include a charger noise generated when the battery is charged, and the charger noise may be classified as the worst type noise.
If a noise is severe, a lead-out circuit for processing the signal of sensing lines of a touch screen panel does not accurately recognize electric charges included in the sensing line. As a result, an error may occur in the touch recognition of a touch screen due to a noise.